Rock climbing is ___ great fun.You will get close to ___ nature and take adventures at the same time

题目

Rock climbing is ___ great fun.You will get close to ___ nature and take adventures at the same time.
A / ; /
B a ; /
C a ; the
D / ; a
但是fun是不可数名词用做具体的事情时不加冠词吗?

答案

攀岩很有意思,你可以贴近大自然并且爽一把.
其实选B也说得过去,但是单选,A更合适.
因为这里说攀岩很有意思,并不是说攀岩是一项很有意思的活动（如果这样就用a）.
rock climbing is great fun=rock climbing is very interesting.